1. Field of the Invention
The present invention generally relates to structures for linear and rotary electric machines and, more particularly, to an electric machine which has a modular mover iron core structure such that the path of magnetic flux thereof is shortened, thus reducing the size of the machine and mitigating the unbalance of load back electromotive force (back-EMF), compared to a conventional flux reversal electric machine. Furthermore, the present invention provides various modifications of the proposed embodiment of the electric machine. An example of this would be a linear electric machine in which a hinge structure is applied to a modular mover iron core so that the mover can move in a linearly or curved fashion, or a rotary electric machine that is derived from the proposed linear electric machine.
2. Description of the Related Art
Generally, linear electric machines have been widely used for precision position control. A permanent magnet linear synchronous motor is a representative example of such a conventional linear electric machine. However, in a conventional permanent magnet linear synchronous motor, the permanent magnets are provided on a stator. Therefore, as the distance a mover moves increases, the number of permanent magnets used increases, resulting in an increase in production costs. In addition, due to the end effect induced on the entry end and the exit end of the mover, there is pulsation of thrust and normal force. Furthermore, due to the fact that leakage flux from the permanent magnets attached to the stator affects the area close to the machine, it cannot be applied in some fields. Moreover, in the case of a low speed and a high torque direct drive type rotary motor, a large number of poles would be needed. Here, in a conventional electric machine, it is very difficult to increase the number of poles due to structural limitations, and it is also not easy to use a skew structure to reduce pulsations of torque.